PHP中的system()、exec()和shell_exec()有什么区别?

It is possible to run an external command by three PHP functions of

可以通过三个PHP函数运行一个外部命令

system();
exec();
shell_exec();

but what are their differences? In spite of their specific applications, in most cases, the can be equally used. I am curious to know which is preferred one when they can be equally used. For example, for unzipping a file or compressing a folder (with tar command), which one is preferred (probably from performance point of view)?

但是他们有什么不同呢?尽管它们有特定的应用程序，但在大多数情况下，可以使用相同的方法。我很想知道，当它们可以被同等使用时，哪一个是首选的。例如，对于解压缩文件或压缩文件夹(使用tar命令)，首选哪个文件(可能从性能角度来看)?

UPDATE: In another question, I found a very useful link describing different aspects for these functions. I share the link here, as other may use to better understand security issues and other aspects.

更新:在另一个问题中，我发现了一个非常有用的链接，用于描述这些函数的不同方面。我在这里分享链接，因为其他可能用来更好地理解安全问题和其他方面。

1 个解决方案

#1

exec — Execute an external program

执行一个外部程序

system — Execute an external program and display the output

系统-执行一个外部程序并显示输出

shell_exec — Execute command via shell and return the complete output as a string

shell_exec -通过shell执行命令，并以字符串形式返回完整的输出

so if you don't need the output, I would go with exec.

如果你不需要输出，我就用exec。

Further details:

进一步的细节:

http://php.net/manual/en/function.exec.php
http://php.net/manual/en/function.exec.php
http://php.net/manual/en/function.system.php
http://php.net/manual/en/function.system.php
http://php.net/shell_exec
http://php.net/shell_exec

#1